mosaic.glmlist {vcdExtra}

Mosaic Displays for glmlist and loglmlist Objects

Description

This function provides a convenient interface for viewing mosaic displays associated with a collection of glm models for frequency tables that have been stored in a glmlist or loglmlist object. You can plot either selected models individually, or mosaics for all models in an array of viewports.

Usage

## S3 method for class 'glmlist'
mosaic(x, selection, 
  panel=mosaic,
  type=c("observed", "expected"), 
  legend=ask | !missing(selection),
  main=NULL,
  ask=TRUE, graphics=TRUE, rows, cols, newpage=TRUE,
  ...)

## S3 method for class 'loglmlist'
mosaic(x, selection, 
  panel=mosaic,
  type=c("observed", "expected"), 
  legend=ask | !missing(selection),
  main=NULL,
  ask=TRUE, graphics=TRUE, rows, cols, newpage=TRUE,
  ...)

Arguments

x

a glmlist or loglmlist object

selection

the index or name of one glm or loglm object in x. If no selection is specified, a menu of models is presented or all models are plotted.

panel

a strucplot panel function, typically mosaic or sieve

type

a character string indicating whether the "observed" or the "expected" values of the table should be visualized

legend

logical: show a legend for residuals in the mosaic display(s)? The default behavior is to include a legend when only a single plot is shown, i.e., if ask is TRUE or a selection has been specified.

main

either a logical, or a vector of character strings used for plotting the main title. If main is a logical and TRUE, the name of the selected glm object is used.

ask

logical: should the function display a menu of models, when one is not specified in selection? If selection is not supplied and ask is TRUE (the default), a menu of model names is presented; if ask is FALSE, mosaics for all models are plotted in an array.

graphics

logical: use a graphic dialog box when ask=TRUE?

rows, cols

when ask=FALSE, the number of rows and columns in which to plot the mosaics.

newpage

start a new page? (only applies to ask=FALSE)

...

other arguments passed to mosaic.glm and ultimately to mosaic.

Details

Most details of the plots produced can be controlled via ... arguments as shown in some of the examples below. In particular, with panel=sieve you need to also pass gp=shading_Friendly to get a color version.

Value

Returns the result of mosaic.glm.

Author(s)

Michael Friendly

References

David Meyer, Achim Zeileis, and Kurt Hornik (2006). The Strucplot Framework: Visualizing Multi-Way Contingency Tables with vcd. Journal of Statistical Software, 17(3), 1-48. doi:10.18637/jss.v017.i03, available as vignette("strucplot", package="vcd").

See Also

glmlist, loglmlist, Kway

mosaic.glm, mosaic, strucplot, for the many parameters that control the details of mosaic plots.

Examples

data(JobSatisfaction, package="vcd")

# view all pairwise mosaics
pairs(xtabs(Freq~management+supervisor+own, data=JobSatisfaction), 
    shade=TRUE, diag_panel=pairs_diagonal_mosaic)

modSat <- Kway(Freq ~ management+supervisor+own, data=JobSatisfaction, 
               family=poisson, prefix="JobSat")
names(modSat)

## Not run: 
mosaic(modSat)              # uses menu, if interactive()

## End(Not run)
mosaic(modSat, "JobSat.1")  # model label
mosaic(modSat, 2)           # model index

# supply a formula to determine the order of variables in the mosaic
mosaic(modSat, 2, formula=~own+supervisor+management)

mosaic(modSat, ask=FALSE)   # uses viewports 

# use a different panel function, label the observed valued in the cells
mosaic(modSat, 1, main=TRUE, panel=sieve, gp=shading_Friendly, labeling=labeling_values)

data(Mental)
indep <- glm(Freq ~ mental+ses,
                family = poisson, data = Mental)
Cscore <- as.numeric(Mental$ses)
Rscore <- as.numeric(Mental$mental)

coleff <- glm(Freq ~ mental + ses + Rscore:ses,
                family = poisson, data = Mental)
roweff <- glm(Freq ~ mental + ses + mental:Cscore,
                family = poisson, data = Mental)
linlin <- glm(Freq ~ mental + ses + Rscore:Cscore,
                family = poisson, data = Mental)

# assign names for the plot labels
modMental <- glmlist(Indep=indep, ColEff=coleff, RowEff=roweff, `Lin x Lin`=linlin)
mosaic(modMental, ask=FALSE, margins=c(3,1,1,2), labeling_args=list(abbreviate_labs=5))